On the minimum dark matter mass testable by neutrinos from the Sun

Abstract

We discuss a limitation on extracting bounds on the scattering cross section\nof dark matter with nucleons, using neutrinos from the Sun. If the dark matter\nparticle is sufficiently light (less than about 4 GeV), the effect of\nevaporation is not negligible and the capture process goes in equilibrium with\nthe evaporation. In this regime, the flux of solar neutrinos of dark matter\norigin becomes independent of the scattering cross section and therefore no\nconstraint can be placed on it. We find the minimum values of dark matter\nmasses for which the scattering cross section on nucleons can be probed using\nneutrinos from the Sun. We also provide simple and accurate fitting functions\nfor all the relevant processes of GeV-scale dark matter in the Sun.\n